Specifications_and_Requirements.pdf

FY24 Performance Work Statement for DAS Multi‐Fiber Interrogator Purchase

1.0 Introduction and Background

The USGS operates the ShakeAlert Earthquake Early Warning (EEW) system in CA, OR, and WA. Offshore earthquakes in these states pose significant seismic hazard and are challenging to provide timely warnings for due to the lack of offshore seismic and geodetic instrumentation. A potential solution to this problem results from the fiber-optic cables installed on the seafloor offshore of a growing number of west coast cities. The Distributed Acoustic Sensing (DAS) technology uses lasers to interrogate a fiber at a high-rate and detects the passing of seismic waves through the cable. There are numerous basic research questions to be investigated to determine if this is a viable technology for ShakeAlert. Typically, multiple submarine cables will land at the same location/landing station and be joined into an extensive onshore fiber-optic network. An ideal DAS based EEW system would be able to interrogate a number of these fibers/cables simultaneously from one location to allow for robust event detection, and accurate source characterization including location and magnitude. Additionally, it would make the data from multiple fibers available in real-time to processing algorithms running on a server that is tightly integrated into the data acquisition system to minimize the delays associated with data transfer and input/output.

2.0 Scope

The awardee will provide USGS with a Distributed Acoustic Sensing (DAS) interrogator capable of monitoring multiple fibers simultaneously, without the need for optical switching by the user, and at 200 samples per second or greater. The unit must be capable of remote operation, remote data access via a web tool, and have sufficient processing capabilities to operate real-time earthquake detection algorithms on 10,000 plus channels.

3.0 Applicable Documents-N/A

4.0 Technical Requirements

The interrogator manufacturer will have a demonstrated track record of collecting earthquake datasets that are of sufficient quality to enable reliable source parameter estimates and sufficient quality to pass scientific peer review with the proposed interrogator or a directly related earlier generation system.

The interrogator unit will be delivered before December 2024.

The interrogator unit will be able to collect data on at least four fibers simultaneously at 200 samples per second or higher rate, without the need for optical switching by the user.

The interrogator unit will be coupled with a linux based processing system capable of running customized real-time monitoring and earthquake detection algorithms designed by USGS and other groups.

The interrogator unit will be able to collect high quality earthquake waveforms out to distances of at least 100 km from the interrogator and have configurable gauge lengths.

The interrogator will have recording disk capabilities of at least 50 TB.

The interrogator will be easily interfaceable with an online web tool portal to perform general data inspection, state-of-health monitoring, and rapid access to data windows for each detected event during the deployment.

The interrogator unit should be mountable in a standard computer rack and connect to fibers with industry standard connectors.

Potential to modify/upgrade the system with the ability to convert to using an L-band laser if required for a specific fiber would be desirable but is not strictly required.

Potential to modify/upgrade the system to interrogate with two different gauge lengths simultaneously would be desirable but is not strictly required.

5.0 Deliverables

The awardee will provide the USGS with a DAS interrogator meeting the above specifications along with all necessary peripherals.

The awardee will assist in the initial installation of the system for its first deployment and provide sufficient documentation on the operation of the system.